Journal List > J Korean Acad Prosthodont > v.55(3) > 1034938

Yoo, Kim, and Yoon: Overdentures using newly designed metal ball attachment containing predetermined gap with stress breakers


Several types of attachments have been used for implant supported and/or retained overdentures. Locator is one of the stud type attachments and it has been generally used. However, the colored matrix is resilient and vulnerable to wear, so frequent post-insertion maintenance is needed. To solve this problem, it is necessary to introduce innovative attachment system. Overdentures using Air Gap attachment (AGA) has improved masticatory function and facial esthetics. AGA is made of metal, so it could be more resistant to wear or friction than the other resilient attachments. Nevertheless, AGA plays a role in stress breakers because it allows movement during denture movement with predetermined gap. In addition, both pre-existing implants and natural teeth were successfully used for connection of AGA. AGA could replace other unsplinted type of attachments. Overdentures using AGA could provide satisfactory result in terms of function, esthetics and retention. However, long term follow up is needed.

Figures and Tables

Fig. 1

AGA system. (A) Components of AGA system, (B) Assembly of AGA components, (C) Schematic diagram of lap procedure of AGA. Dotted arrow indicates the-space between AGA and denture base. a: housing; b: transfer abutment; c: AGA holder; d: lab analogue holder; e: transfer abutment screw; f: AGA keeper; g: lab analogue.

Fig. 2

Connection of AGA matrix. (A) AGA housing is connected to the intaglio surface of denture, (B) Tightening of AGA holder. The AGA holder is connected to the housing attached to the resin base using a 1.2 mm hex driver. When replacement of the matrix is required, only the corresponding component can be easily replaced using a driver. (C) Assembled AGA matrix.

Fig. 3

Case 1. (A) Pre-operative panoramic radiograph, (B) Post-operative panoramic radiograph, (C) Definitive impression, (D) Boxing, (E) Definitive model, (F) Metal framework try-in, (G) Delivery (intraoral), (H) Delivery (extraoral).

Fig. 4

Case 2. (A) Pre-operative panoramic radiograph, (B) Frontal view, (C) Right buccal view, (D) Left buccal view, (E) Mandibular occlusal view, (F) Intaglio surface of definitive prosthesis.

Fig. 5

Case 3. (A) Pre-operative periapical radiograph, (B) Periapical radiograph after endodontic treatment, (C) Post-operative periapical radiograph, (D) Left buccal view after the engagement of AGA, (E) Frontal view after the placement of repaired prosthesis, (F) Left buccal view after the placement of repaired prosthesis, (G) Maxillary occlusal view after the placement of repaired prosthesis, (H) Intaglio surface of repaired prosthesis.



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Jin-Joo Yoo

Man-Yong Kim

Joon-Ho Yoon

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